1. Technical Field
This application relates to a surgical stapling apparatus, and more particularly, to an articulating endoscopic surgical stapling apparatus which sequentially applies a plurality of surgical fasteners to body tissue and subsequently incises the fastened tissue.
2. Background of Related Art
Surgical devices wherein tissue is first grasped or clamped between opposing jaw structure and then joined by surgical fasteners are well known in the art. Typically, a knife is employed after the tissue is fastened to cut the tissue along a preferred cutting path. The fasteners are typically in the form of surgical staples but other types of fasteners can also be utilized to accomplish the same or similar purpose.
Instruments for this purpose can include two elongated members which are respectively used to capture or clamp tissue. Typically, one of the members carries a staple cartridge which houses a plurality of staples arranged in at least two lateral rows while the other member has an anvil that defines a surface for forming the staple legs as the staples are driven from the staple cartridge. Generally, the stapling operation is effected by cam bars or sleds that have cam surfaces that travel longitudinally through the staple cartridge and staple pushers that sequentially eject the staples from the staple cartridge. Typically, a knife travels between the staple rows to longitudinally cut and/or open the stapled tissue between the rows of formed staples.
One of the issues associated with prior stapler designs is the tendency for the dynamic clamping member to skew or buckle as it passes through the tissue due to the large forces generated during stapling and cutting tissue. For example, prior dynamic clamping member designs that carry the knife or cutting surface provide cantilever-like designs which are designed to effectively squeeze tissue ahead of the knife blade and the staple forming sled to force fluids from the tissue which enhances tissue stapling and contributes to a successful tissue staple. However, the large forces required to staple and incise tissue tend to place undue stresses on the cantilever knife design which may cause the knife to skew or buckle during translation often requiring the surgeon to fire the stapler very slowly through larger tissue structures to avoid the possibility of the knife traveling off line.
It is an object of this disclosure to provide a surgical stapler having an actuator, preferably, a dynamic clamping member which enhances tissue stapling by forcing fluids out of the clamped tissue before ejecting stapling into and stapling the tissue. Another object of this disclosure is to provide a dynamic clamp member that applies substantially clamping pressure upon the anvil and cartridge assembly of the tool member of a surgical stapler as the dynamic clamping member translates along and through the tool assembly.
Another object of this disclosure is to provide a dynamic clamping member that helps to provide a uniform tissue gap between the tissue contacting surfaces of an anvil and a staple cartridge in the immediate area of and during sequential, progressive staple formation and tissue fastening, as well as in the area of and during tissue cutting, if cutting is being performed.